1. Field of the Inventive Concepts
The inventive concepts disclosed herein relate generally to seats for ball valves, and more particularly, but not by way of limitation, to an improved seat assembly for a trunnion mounted ball valve wherein the seat assembly is capable of distributing sealant injected through a sealant injection port.
2. Brief Description of Related Art
In the typical construction of a trunnion mounted ball valve, the ball is machined to provide “trunnions” that are mounted in bearings. The bearing-trunnion combination is intended to support the ball in a stationary position relative to the flow path, but allow rotation of the ball. The ball engages a pair of seat assemblies to form a seal around the ball. The seat assemblies typically include an annular seat carrier and an annular seat positioned in a groove formed in the seat carrier.
Trunnion mounted ball valves are often used in harsh, corrosive environments, such as found in the oil and gas industry. Consequently, the interior faces of the metal portions of the valve body and ball valve member which are exposed to the oil and gas are subject to corrosion, which after an extended period of time without movement of the ball can result in seizure of the ball valve member making it difficult and, at times, impossible to open or close. Also, damage from foreign objects and corrosion of metal parts quite often results in leakage after a frozen valve is opened or closed.
It has long been known to provide valves with a port for introducing a viscous lubricant, commonly referred to in the art as a sealant, between portions of the seal assemblies and the surface of the valve member. While the injection of sealant into a valve often produces desired results, there are other times when a valve remains frozen or continues to leak. One reason for this is that sealant is often injected at one point in a way that sealant is not evenly distributed about the seal assemblies. As such, sealant may be injected into a valve at a location that does not require the sealant, while the location where the sealant is needed does not receive a sufficient amount of sealant.
To this end, a need exists for an improved seat assembly for distributing sealant around the seals. It is to such an improved seat assembly that the inventive concepts disclosed herein are directed.